Thermal joint compounds are used to improve the transfer of thermal energy by filling the minute air gaps between metal-to-metal surfaces, such as exist between the thermoelectric elements and heat exchangers of thermoelectric heat pumps. Existing thermal joint compounds have a white, greasy appearance. The material because of its greasy characteristic is difficult to handle without soiling the user's clothes, uncovered portions of the user's body, and the user's work station. Owing to the white color, these soiled areas are made very conspicuous. In addition the white color can detract from the desired cosmetics of the end product, thereby tending to limit the commercial applications for thermoelectric coolers.
This color related problem with existing thermal joint compounds has been recognized and at least one attempt to solving the problem has been made as evidenced by an existing product on the market containing a coloring ingredient.
A disadvantage attending the use of the existing colored product is that with the passage of time the coloring agent separates from the compound as a liquid. This color separation fades the color of the compound to an off shade of white as well as freeing the liquid coloring for soiling anything or anybody coming in contact with it.
A principal difference between the colored thermal joint compound and the prior art compound is that separation of the coloring agent from the thermal joint compound is substantially eliminated. Thus, after a storage period a remixing process is not required immediately prior to use, and the cosmetic effect achieved with its use does not deteriorate with time owing to color separation with time.
A principal reason in the coloring of the thermal compound is to relate visually to the temperatures of the TE cooling system (i.e. blue for cool; red for hot temperatures) for assembly purposes, and for marketing the products.